Wireline well abandonment tool

ABSTRACT

A well abandonment tool comprising an elongate housing extending between top and bottom ends locatable within a wellbore having a longitudinal pumping cylindrical bore therein. The apparatus further comprises a wellbore seal located around the housing operable to engage upon the wellbore and to be expanded into contact therewith upon an upward motion of the housing so as to seal an annulus between the housing and the wellbore and a bridge plug engagement connector adapted to secure a bridge plug thereto at a position below the bottom end of the housing. The apparatus further includes a pumping piston longitudinally moveably located within the pumping cylinder, the pumping piston being suspended from a wireline wherein longitudinal movement of the pumping piston discharges a fluid into a bridge plug activation chamber having a movable cylinder adapted to draw the bridge plug engagement connector against the bottom end of the housing so as to expand the bridge plug into engagement with the wellbore. A method for abandoning a wellbore comprising locating a housing within a wellbore above a location to be sealed, pulling upwardly on a wireline secured to a pumping piston within the housing so as to draw a bottom end of the housing upwards thereby extending a seal element located along the housing into engagement with the wellbore, pulling upwardly on the wireline so as to displace the pumping piston within a cylindrical bore within the housing so as to discharge a fluid therefrom and directing the discharged fluid into a bridge plug activation chamber adapted to draw a bridge plug engagement connector against a bottom end of the housing so as to expand a bridge plug secured thereon into engagement with the wellbore.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/342,180 filed Apr. 15, 2019 entitled Wireline Well Abandonment Toolwhich is a 371 of international application no. PCT/CA2017/051228 filedOct. 16, 2017 entitled Wireline Well Abandonment Tool which claimspriority to U.S. provisional patent application No. 62/408,178 filedOct. 14, 2016 entitled Wireline Well Abandonment Tool.

BACKGROUND OF THE INVENTION 1. Field of Invention

The present invention relates generally to containment and sealing ofsuspended oil wells and gas wells and more specifically to downholetools for setting and pressure testing wellbore sealing plugs duringsealing and abandonment of oil wells and gas wells, and to methods foruse of said tools.

2. Description of Related Art

Recovery of hydrocarbon-rich crude oil and/or gas from subterraneandeposits is accomplished through wellbores that have been drilled intothe deposits from the earth's surface. Before crude oil and/or gas canbe extracted from a subterranean deposit, the wellbore must be“completed” so that the hydrocarbon-rich materials can be removed fromthe deposit without leakage into the subterranean zones between thedeposit, potable surface ground water, and the earth's surface.Completion of a wellbore and making it production ready for extractionof the hydrocarbon-rich material generally involves: (i) inserting anouter casing into the wellbore so that it terminates at about the regionbelow the deposit, (ii) cementing the space, also referred to as the“annulus”, between the casing and the wellbore, (iii) perforating theproduction casing to expose the hydrocarbon rich material in the regionto the inside of the casing, and (iv) inserting a narrower diameter“production tubing” through the casing until it terminates within thesubterranean deposit, to allow the hydrocarbon rich material to flow tosurface.

All wells have an operational lifetime after which they become: (i)unproductive due to depletion of the hydrocarbon-rich material, oralternatively, (ii) unprofitable to operate due to fluctuations in theglobal prices for crude oil and/or gas in combination with theoperations costs required to keep a well in production. Such conditionscan result in decisions to shut-in producing wells, i.e., to ceasepumping operations. Three months after a well is shut-in, it is referredto as a “suspended well”.

Most jurisdictions have regulations in place that stipulate theprocedures that must be followed to close and seal suspended or shut-inwells to minimize as much as possible any leakage and/or seepage ofremaining subterranean hydrocarbon-rich materials into other zonesbetween the deposits and the earth's surface, and in particular, toprevent the contamination of aquifers and ground water.

However, there is an enormous backlog of suspended wells that have notbeen sealed or which have been improperly sealed, in mosthydrocarbon-producing regions around the world. Alberta Environment andParks estimated in 2014 that there were over 50,000 suspended oil andgas wells in that Province(http://globalnews.ca/news/2307275/interactive-the-hidden-cost-of-abandoned-oil-and-gas-wells-in-alberta/).Wells that have not been abandoned about ten years after they weresuspended become a government responsibility and liability, and areconsidered to be “orphan wells”. The downturn in global oil prices in2014-2015 resulted in the shut-in of over 500 wells in Alberta during2015 with another 1,200 new orphan wells identified in 2016 that werelicensed to defunct Alberta licensees (according to the Orphan WellAssociation). In other jurisdictions, State agencies report that over6,800 orphan wells are known to exist in Texas, and that there arenearly 1,000 orphan wells in California.

The Alberta Energy Regulator issued Directive 20 in March 2016 that setout the requirements for abandoning shutdown wells(https://www.aer.ca/rules-and-regulations/directives/directive-020). Thecurrent requirements for sealing Level-A intervals in completed wellsspecify three options for sealing a production casing or tubing wherein:(i) the first option comprises setting a cement retainer within 15 m ofthe perforations in a production zone, (ii) the second option is settinga cement squeeze into the perforations in a production zone and mustextend a minimum of 15 vertical metres below the completed interval anda minimum of 30 vertical metres above the completed interval, and (iii)the third option is setting a plug in a permanent bridge plug within 15m of the perforations in a production zone. Regardless of which optionis selected for sealing the production casing, the plug must be pressuretested at stabilized pressure of 7000 kPa for 10 min. In the case offirst option, if the cement retainer passes the pressure test, then acement squeeze must be conducted through the retainer followed bycapping with class “G” cement that is a minimum of 30 vertical metres.In the case of the third option, if the permanent bridge plug passes thepressure test, then it must be capped with 60 vertical metres of class“G” cement.

The current requirements for non-level A wells specify four options forsealing a production casing wherein: (i) the first option comprisessetting a permanent bridge plug within 15 m of the perforations in aproduction zone, (ii) the second option is setting a cement retainerwithin 15 m of the perforations in a production zone, (iii) the thirdoption is setting a plug in a permanent packer within 15 m of theperforations in a production zone, and (iv) the fourth option is settinga cement plug across the perforations in a production zone wherein thecement plug must extend a minimum of 15 vertical metres below thecompleted interval and a minimum of 15 vertical metres above thecompleted interval. Regardless of which option is selected for sealingthe production casing, the plug must be pressure tested at stabilizedpressure of 7000 kPa for 10 min. If the plug passes the pressure test,then it must be capped with 8 vertical metres of class “G” cement oralternatively, with a minimum of 3 vertical metres of resin-basedlow-permeability gypsum cement.

The most common practices for sealing and pressure testing cased andcemented natural gas wells or oil wells use tubing-conveyed packerassemblies to pressure test abandonment Bridge Plugs. This requiresdeployment of tubing runs into the wells from over-the-road coil casingunits or service rigs through which: (i) the sealing materials aredelivered and installed, and then (ii) pressure-testing equipment aredeployed and recovered. Over-the-road coil tubing units generallycomprise a heavy-duty truck chassis with tandem steering and tandemdrive axle or alternatively a tridem drive axle, onto which aretypically installed a coiled casing package that includes an injector, acoiled tubing reel, a soap pump and tank, a compressor, a picker, ablow-out preventer, and optionally, a control cabin and/or or atelescoping operator's station. To properly service oil and gas wellsand to abandon suspended wells, a number of other service rigs arerequired on site in addition to coil tubing units, including (i) acarrier rig for the derrick, (ii) a pump truck, (iii) a “doghouse” forcrew use, and (iv) support trucks with tools, equipment, and powergenerators. Such combinations of services rigs and over-the-road coiltubing units are expensive to transport and operate, and the cost oftheir use to seal and test an abandoned well is typically in the rangeof $10,000 to $20,000 per day.

SUMMARY OF THE INVENTION

According to a first embodiment of the present invention there isdisclosed a well abandonment tool comprising an elongate housingextending between top and bottom ends locatable within a wellbore havinga longitudinal pumping cylindrical bore therein. The apparatus furthercomprises a wellbore seal located around the housing operable to engageupon the wellbore and to be expanded into contact therewith upon anupward motion of the housing so as to seal an annulus between thehousing and the wellbore and a bridge plug engagement connector adaptedto secure a bridge plug thereto at a position below the bottom end ofthe housing. The apparatus further includes a pumping pistonlongitudinally moveably located within the pumping cylinder, the pumpingpiston being suspended from a wireline wherein longitudinal movement ofthe pumping piston discharges a fluid into a bridge plug activationchamber having a movable cylinder adapted to draw the bridge plugengagement connector against the bottom end of the housing so as toexpand the bridge plug into engagement with the wellbore.

The bridge plug engagement connector may include a frangible portion andwherein the bridge plug engagement connector may include a cavitytherein through the frangible portion in fluidic communication with thebridge plug activation chamber. The well abandonment tool may furthercomprise at least one valve adapted to selectably direct the fluid fromthe pumping cylinder to the bridge plug activation chamber. The at leastone valve may be adapted to isolate the fluid within the pumpingcylinder so as to prevent movement of the pumping piston therein.

The well abandonment tool may further comprise a testing fluid injectorassembly adapted to discharge a quantity of a testing fluid therefrominto a pressurized annulus between the housing and the wellbore andbetween the wellbore seal and the bridge plug. The testing fluidinjector may comprise an injector cylinder having an injector pistontherein and a reservoir cylinder having a reservoir piston therein. Thereservoir piston may be displaced by the fluid directed to the bridgeplug activation chamber so as to pressurize the injector cylinder. Theat least one valve may be adapted to selectably direct the fluid to theinjector piston so as to displace the piston therein so as to dischargethe testing fluid therefrom. The injector cylinder may include a checkvalve having an opening pressure selected to prevent the discharge ofthe testing fluid before the bridge plug is set.

The well abandonment tool may further comprise a processing circuitadapted to control the operation of the at least one valve. Theprocessing circuit may be adapted to monitor the pressure within thepressurized annulus and presence of the testing fluid at the testsensors thereabove.

The pumping piston may include a first stage ring selectably securedtherearound so as to provide an increased pumping volume when securedthereto. The first stage ring may include a plurality of piston colletarms each having a radially inwardly extending protrusion engaged withinan annular piston groove on the pumping piston so as to secure thesecond stage ring to the pumping piston. Each of the pumping pistoncollet arms may include a radially outwardly extending protrusionadapted to be engaged within an annular cylinder groove in the pumpingcylinder.

The well abandonment tool may further comprise a first stagedisengagement wedge ring adapted to be slidably located under theplurality of piston collet arms so as to disengage the inwardlyextending protrusions from the annular piston groove and engage theoutwardly extending protrusions into the annular cylinder groove. Thewell abandonment tool may further comprise at least one spring biasedsecond stage piston fluidically connected with the output from thepumping cylinder so as to displace the first stage disengagement wedgering upon the pumping cylinder reading a predetermined pressure.

The well abandonment tool may further comprise a plurality of slip armsexpandable into engagement with the wellbore wall by a cone locatedaround the housing between the slip arms and the wellbore seal. The sliparms may be retained around the housing on a slip arm ring. The slip armring may include at least one radially inwardly extending j-pin, whereinthe slip arm ring is selectably longitudinally positionable along thehousing by rotating the j-pin into alternating short and longlongitudinal slots on an outer surface of the housing.

The wellbore seal may be longitudinally compressed between the cone anda wellbore seal backing protrusion extending from the housing. The wellabandonment tool may further comprise a wellbore seal retention pistonengaged upon a bottom end of the wellbore seal wherein the wellboreretention piston is biased towards the wellbore seal by the pressure ofthe fluid directed towards the bridge plug engagement chamber.

According to a further embodiment of the present invention there isdisclosed a method for abandoning a wellbore comprising locating ahousing within a wellbore above a location to be sealed, pullingupwardly on a wireline secured to a pumping piston within the housing soas to draw a bottom end of the housing upwards thereby extending a sealelement located along the housing into engagement with the wellbore,pulling upwardly on the wireline so as to displace the pumping pistonwithin a cylindrical bore within the housing so as to discharge a fluidtherefrom and directing the discharged fluid into a bridge plugactivation chamber adapted to draw a bridge plug engagement connectoragainst a bottom end of the housing so as to expand a bridge plugsecured thereon into engagement with the wellbore.

The method of may further comprise further pressurizing the bridge plugactivation chamber after the bridge plug is secured so as to shear afrangible portion of the bride plug engagement connector releasing thefluid into a pressurized annulus between the housing and the wellborebetween the seal and the bridge plug.

The method may further comprise injecting a quantity of a testing fluidinto the pressurized annulus and monitoring above the seal for apresence of the testing fluid. The method may further comprisemonitoring a pressure within the pressurized annulus.

According to a further embodiment of the invention, there is disclosed adownhole pressure-testing tool comprising a chassis, a motor securelyengaged within the chassis, a pump securely engaged within the chassisand in communication with the motor to provide fluid pressures therefromand a radially expandable and contractible sealing packing securelyengaged within and to the chassis. The sealing packing is expandablewith a first pressure and contractible when the first pressure isrelieved. The downhole pressure-testing tool further comprises aradially expandable and contractible hydraulic slip or a mechanical slipsecurely engaged with the chassis and extending outward therefrom and afirst set of a pressure sensor and a temperature sensor extending belowthe pump and wherein the pressure-testing tool is deployable into aproduction casing from a wireline service truck. The pressure-testingtool is in communication with and controlled by instrumentation providedtherefore in the wireline service truck wherein the the pressure-testingtool is sealingly engageable within a production casing with a hydraulicpressure or a mechanical pressure for radially expanding the sealingpacking. The pressure-testing tool is configured for providing a secondfluid pressure greater than the first fluid pressure to a lower portionof the production casing.

The downhole pressure-testing tool may further comprise a second set ofa pressure sensor and a temperature sensor extending above the motor.

Other aspects and features of the present invention will become apparentto those ordinarily skilled in the art upon review of the followingdescription of specific embodiments of the invention in conjunction withthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention whereinsimilar characters of reference denote corresponding parts in each view,

FIG. 1 is a schematic illustration of a wireline pressure-testing toolaccording to an embodiment of the present disclosure, deployed into aproduction casing above a permanent bridge plug.

FIG. 2 is a close-up cross-sectional longitudinal view of a wirelinepressure-testing tool according to another embodiment of the presentdisclosure, deployed into a production casing.

FIG. 3 is a schematic illustration of a wireline pressure-testing toolaccording to an embodiment of the present disclosure, deployed into aproduction casing above a permanent cement retainer.

FIG. 4 is a perspective view of a wireline well abandonment toolaccording to a further embodiment of the invention.

FIG. 5 is an end view of the wireline well abandonment tool of FIG. 4.

FIG. 6 is a side plane cross-sectional view of the wireline wellabandonment tool taken along the line 6-6 of FIG. 5.

FIG. 7 is a side plane cross-sectional view of the top connectionsection taken along the line 6-6 of FIG. 5.

FIG. 8 is a detailed top plane cross-sectional view of the topconnection section taken along the line 8-8 of FIG. 5.

FIG. 9 is an end view of the upper housing, as viewed along the line 9-9of FIG. 8.

FIG. 10 is an end view of the upper housing, as viewed along the line10-10 of FIG. 8.

FIG. 11 is a top plane cross-sectional view of the pump taken along theline 8-8 of FIG. 5.

FIG. 12 is a side plane cross-sectional view of the pump taken along theline 6-6 of FIG. 5.

FIG. 13 is a detailed top plane cross-sectional view of the releasablepump collar taken along the line 8-8 of FIG. 5.

FIG. 14 is a detailed side plane cross-sectional view of the releasablepump collar taken along the line 6-6 of FIG. 5.

FIG. 15 is a side plane cross-sectional view of the valve taken alongthe line 6-6 of FIG. 5.

FIG. 16 is a top plane cross-sectional view of the valve taken along theline 8-8 of FIG. 5.

FIG. 17 is a diagonal plane cross-sectional view of the valve takenalong the line 17-17 of FIG. 5.

FIG. 18 is a schematic of the valve in a first or placement position.

FIG. 19 is a schematic of the valve in a second or sealing element setposition.

FIG. 20 is a schematic of the valve in a third or pressurizing position.

FIG. 21 is a schematic of the valve in a fourth or release position.

FIG. 22 is a side plane cross-sectional view of the slip collet and conetaken along the line 6-6 of FIG. 5.

FIG. 23 is a perspective view of the main mandrel.

FIG. 24 is a top plane cross-sectional view of the sealing element andfluid test chamber taken along the line 8-8 of FIG. 5.

FIG. 25 is a top plane cross-sectional view of the bridge plug pistontaken along the line 8-8 of FIG. 5.

FIG. 26 is a top-plane cross-sectional view of the slip collet in aretention position taken along the line 8-8 of FIG. 5.

FIG. 27 is a top-plane cross-sectional view of the top connectionsection in a fully extended low-pressure pumping position taken alongthe line 8-8 of FIG. 5.

FIG. 28 is a top-plane cross-sectional view of the sealing element andfluid test chamber in a set position taken along the line 8-8 of FIG. 5.

FIG. 29 is a top-plane cross-sectional view of the bridge plug piston ina set and pressure testing position taken along the line 8-8 of FIG. 5.

FIG. 30 is a detailed side plane cross-sectional view of the releasablepump collar in a high-pressure pumping position taken along the line 6-6of FIG. 5.

FIG. 31 is a detailed top-plane cross-sectional view of fluid testchamber in an injected position taken along the line 8-8 of FIG. 5.

FIG. 32 is a detailed side view of the collet arms and collet cage ofthe apparatus of FIG. 5.

FIG. 33 is a schematic of the control system for use in the wirelineabandonment tool.

DETAILED DESCRIPTION

The embodiments of the present disclosure generally relate to downholepressure-testing tools that can be deployed into and recovered from asuspended production casing by a wireline service truck for the purposesof testing a sealed, i.e. abandoned, production casing as may berequired by government regulations. The pressure-testing tools disclosedherein can be deployed into a production casing and operated therein,and then recovered with a wireline service truck alone if the wirelineservice truck is additionally fitted with a service rig (i.e. aderrick). Alternatively, the pressure-testing tools may deployed from awireline service truck into a production casing by way of a derrickdeployed from a carrier rig.

One embodiment of a downhole pressure-testing tool disclosed hereincomprises a packer pump assembly having one set and optionally, two setsof temperature and pressure sensors. The packer pump assembly generallycomprises a chassis within which are mounted a pump, a motor to drivethe pump, an expandable/retractable packer seal element for sealinglyengaging/disengaging the entire inner circumference of a productioncasing, and slips to prevent upward movement of the packer pump during apressure test between the plug and the packer pump assembly. One set ofa temperature sensor and a pressure sensor extends below the packer pumpassembly while another set of a temperature sensor and a pressure sensorextends above the packer pump assembly. The two sets of temperature andpressure sensors communicate with gauges and monitors located on thewireline service truck. The operation of the motor and pump as well asthe deployment and retraction of the packer seal element are controlledfrom the controls equipment located on the wireline service truck. Thepressure testing tool also electronically initiates a setting tool toset the permanent plug eliminating the need to perform two wireline runsto set and pressure test the plug.

The pump component of the packer pump assembly may be any pump suitablefor downhole use, for example a mechanical plunger style pump, a fluidpump, and the like. The motor component is an electrical motor thatprovides a rotational force or a piston force or a fluid-pressure basedforce, and the like.

An example of a downhole pressure-testing tool 20 according to anembodiment of the present disclosure is shown in FIG. 1. A productioncasing 10 is shown for extracting hydrocarbon-rich material from twozones accessible through perforations 12 (lower producing zone) and 14(upper producing zone). A permanent bridge plug 16 has been set with thepressure-testing tool 20 above the perforations 12 to seal theproduction casing between the upper and lower producing zones. Thepressure-testing tool 20 is positioned within the production casing 10by a wireline 18 deployed from a wireline service truck (not shown).This pressure-testing tool 20 comprises a chassis 21 within which isengaged a motor 22 and a fluid pump 24. The motor 22 and the fluid pump24 may be coupled together or alternatively, spaced apart. Also engagedwith or alternatively within the chassis 21 is an outwardlyexpandable/retractable packer seal element 26. Also engaged with oralternatively within the chassis 21 are two or more outward-facingoutwardly extendible and retractable slips 28 spaced around the outercircumferential surface of the chassis 21. A first set of pressure andtemperature sensors is housed within a leak-proof casing 30 mounted ontoand extending downward from the chassis 21. A second set of pressure andtemperature sensors may be optionally housed within a leak-proof casing32 mounted onto or about the top surface of the chassis 21.

The deployment and use of the pressure-testing tool 20 is controlledfrom a wireline service truck using standard control devices,instruments, and monitors generally following the methods disclosedherein. After the pressure-testing tool 20 is lowered into theproduction casing 10 to a selected position above the permanent bridgeplug 16, the pressure-testing tool 20 is sealed into place byoperator-controlled expansion of the packer seal element 26 until itsealingly engages the inner circumference of the production casing 10.Then the motor 22 is started and the pump 24 engaged to pump fluid fromthe production casing 10 above the pressure-testing tool 20 into theproduction casing space between the pressure-testing tool 20 and thebridge plug 16 thereby increasing the fluid pressure exerted onto thebridge plug 16. The increasing pressure within the production casing 10space between the pressure-testing tool 20 and the bridge plug 16 andany changes in temperature are detected by the first set of pressure andtemperature sensors housed within casing 30, while the pressure andtemperature of the fluid in the production casing 10 above thepressure-testing tool 20 are detected by the second set of pressure andtemperature sensors housed within casing 32. The pressure andtemperature readings from both sets of sensors are monitored at thesurface by the operator. The operation of the motor 22 and pump 24 iscontinued until the fluid pressure exerted onto the bridge plug 16reaches a target pressure, for example 7000 kPa. Then, the motor 22 andpump 24 are turned off, and the pressure and temperature readings fromboth sets of detectors are monitored and recorded for at least 10minutes to determine if any changes in pressure occur within the spacebetween the pressure-testing tool 20 and the bridge plug 16. If thepressure measured by pressure sensor 30 remains at the target pressurepoint for the duration of the testing interval, e.g., 10 min, then it isconfirmed that the bridge plug 16 has completely and stably sealed theproduction casing 10. However, if the pressure drops below the targetpressure point during the testing interval, then the pressure-testingtool 20 or the bridge plug 16 has to be reset and then retested.

FIG. 2 shows an example of a downhole pressure-testing tool 50 accordingto another embodiment of the present disclosure, shown deployed into aproduction casing 40. This pressure-testing tool 50 comprises a chassis52 within which are mounted a motor 55 operationally engaged with a pump60 by an internal annulus 58 that is fitted with temperature andpressure sensors. The pump 60 has an upper chamber 62 and a lowerchamber 64 defined by a piston retainer shoulder 82 circumferentiallyextending inward into the chambers 62, 64. A spring 84 biases a firstpiston 80 upwardly against the piston retainer shoulder 82. A bottom subhousing 68 is secured to the bottom of the pump 60 by a retainer nut 70.One or more ports 66 extend through the pump 60 housing near its bottomend. A cylinder 85 with a second piston 86 is housed within the cylinder85. O-rings 90 a are provided at the juncture between the bottom subhousing 68 and the cylinder 85, and O-rings 90 b are provided betweenthe cylinder 85 and the second piston 86 to make these juncturesleak-proof. The second piston 86 has plunger shoulders 88 extendingradially outward near its top end and bottom end designed to balancepressure between the sealing packing 78 and pressure below thepressure-testing tool 50. A radially expanding sealing packing 78extends around the outer circumference of the pump 60 housing and issecurely fixed to a lower portion of the pump 60 with a gauge ring 72,and is securely fixed to a lower portion of the motor 55 with a gaugering 74 that cooperates with a spring-retractable hydraulic slip 76.

The deployment and use of the pressure-testing tool 50 is controlledfrom a wireline service truck using standard control devices,instruments, and monitors generally following the methods disclosedherein. The gauge rings 72 and 74 protect the pressure-testing tool 50from physical damage as it is lowered into the production casing 40 to aselected position. After the pressure-testing tool 50 is in position,the spring-retractable hydraulic slip 76 is deployed outward by thefirst piston 80 to radially expand the sealing packing 78 against theinner circumference of the production casing 40, by forcing the flow offluid from the lower chamber 64 of the pump 60 through ports 66 (shownby the line with arrows 105). The motor 55 provides the mechanical forcethrough the annulus 58 to pressurize the fluid in the upper chamber 62that forces the first piston 80 down against the spring 84. After thepressure delivered to the upper chamber 62 from the motor 55 has forcedthe first piston 80 to sealingly engage the sealing packing 78 with theproduction casing 40, increasing the pressure delivered to the upperchamber 62 by the motor 55 will then force the second piston 86 to exertpressure into the production casing space between the pressure-testingtool 50 and a bridge plug or alternatively, a cement plug, oralternatively, a cement retainer, until a target pressure level has beenreached, for example 7000 kPa. Then, the motor 55 and pump 60 are turnedoff, and the pressure and temperature readings from a set of detectorsextending from and below the pressure-testing tool 50 and from a set ofdetectors positioned above the pressure testing tool 50 are monitoredand recorded for at least 10 minutes to determine if any changes inpressure occur within the space between the pressure-testing tool 50 andthe bridge plug or the cement plug or the cement retainer. If thepressure in the production casing between the pressure-testing tool 50and the bridge plug or the cement plug or the cement retainer remains atthe target pressure point for the duration of the testing interval,e.g., 10 min, then it is confirmed that production casing 40 has beencompletely and stably sealed. However, if the pressure drops below thetarget pressure point during the testing interval, then the conclusionmust be that the production casing has not been adequately sealed andthat the pressure-testing tool 50 or the bridge plug or the cement plugor the cement retainer has to be reset and then retested.

FIG. 3 shows another example of a downhole pressure-testing tool 120disclosed herein, deployed into a production casing 110 having a firstset of perforations 112 communicating with a lower producing zone, and asecond set of perforations 114 communicating with a producing zonecloser to the surface. A bridge plug 116 has been installed and sealedinto the production casing 110 just above the first set of perforations112 and beneath the surface 155 of the fluid resident in the productioncasing 110. This pressure-testing tool 120 comprises a chassis 121within which is engaged a motor 122 operationally engaged with a pump124, and a radially expanding sealing packing 126 that has beensealingly engaged with the internal circumference of the productioncasing 110. The pressure-testing tool 120 is connected through awireline cable head 130 to a wireline cable 118 deployed from a wirelineservice truck. The wireline cable head 130 connects to a number ofsensors and instruments for example a casing collar locator 134, a gammaray sensor/transducer 136, a first pressure sensor/transducer 138, and afirst temperature sensor/transducer 140. Deployed below thepressure-testing tool 120 is a tubing 142 containing therein a secondpressure sensor and a second temperature sensor. Tubing 142 isdemountably engaged with an electric setting tool 144 which in turn, isdemountably engaged with a plug setting sleeve adapter 146.

For use to install and pressure-test a bridge plug 116, as illustratedin FIG. 3, the pressure-testing tool 120 is engaged with an electricsetting tool 144, or alternatively a hydraulic setting tool, which inturn is engaged with a plug-setting sleeve adapter 146. The bridge plug116 is demountably engaged with the plug-setting sleeve adapter 146after which the pressure testing tool 120 assembly with the bridge plug116 attached, is deployed into the production casing 110 from a wirelineservice truck as generally disclosed in Examples 1 and 2 until aselected depth is reached based on correlation of recordings from thecasing collar locator 134 and the gamma ray sensor/transducer 136 withgamma ray data recorded during previous downhole operations, whereby thebridge plug 116 is precisely positioned above a set of perforationse.g., perforations 112 as shown in FIG. 3. The bridge plug 116 is thenset and sealed into place by remote control manipulation from thewireline service truck, of the setting tool 144 and the plug-settingsleeve adapter 146. After the bridge plug 116 has been set and sealed,the plug-setting sleeve adapter 146 is disengaged from the bridge plug116 and the pressure-testing tool 120 is partially recovered to aselected position and distance above bridge plug 116. Thepressure-testing tool 120 is then set and sealed into position withinthe production casing 110 generally following the description providedin the discussion pertaining to FIG. 2, by deploying radially expandingsealing packing 126 and then the slips (not shown). Then, the motor 122and pump 124 cooperate to pump fluid from above the pressure-testingtool 120 into the space between the pressure-testing tool 120 and thebridge plug 116 (following the path with arrows shown as 150) until atarget pressure is reached, for example 7000 kPa. Then, the motor 122and pump 124 are turned off, and the pressure and temperature readingsfrom the second pressure sensor and the second temperature sensor withinthe pressurized zone along with the pressure and temperature readingsfrom the first pressure sensor and the first temperature sensor abovethe pressure-testing tool 120 are monitored for at least 10 minutes todetermine if any changes in pressure occur within the space between thepressure-testing tool 120 and the bridge plug 116. If the pressure inthe production casing 110 between the pressure-testing tool 120 and thebridge plug 116 remains at the target pressure point for the duration ofthe testing interval, e.g., 10 min, then it is confirmed that productioncasing 110 has completely and stably sealed. However, if the pressurewithin the pressurized zone of the production casing 110 drops below thetarget pressure point during the testing interval, then the conclusionmust be that the or pressure-testing tool 120 or the production casing110 has not been adequately sealed and that the bridge plug 116 has tobe reset and retested.

It is to be noted that the downhole pressure-testing tools disclosedherein may be configured to deliver and maintain pressures in zonesbetween the pressure-testing tools and bridge plugs or cement plugs orcement retainers being tested for the integrity of their seals, in therange of 4000 kPa, 5000 kPa, 6000 kPa, 7000 kPa, 8000 kPa, 9000 kPa,10000 kPa, 11000 kPa, 15000 kPa, 20000 kPa, 25000 kPa, 30000 kPa, 35000kPa, and therebetween.

Referring to FIGS. 4 and 6, an apparatus to set and pressure test abridge plug 16 in the production casing 10 of a subterranean wellaccording to a further embodiment of the invention is shown generally at200. The apparatus 200 comprises a substantially elongate cylindricalbody and extends between first and second ends, 202 and 204,respectively, along a central axis 700. The apparatus 200 is comprisedof a top connection section 206 proximate to the first end 202 and abridge plug setting and testing section 208 proximate to the second end204 with a fluid control section 210 and a retention section 212therebetween. The retention section 212 utilizes mechanical forceapplied by the wireline 18 attached to the top connection section 206 toextend and retract a slip collet 214, as will be described in moredetail below. The fluid control section 210 provides hydraulic pressureto expand a sealing element 550 in the retention section 212 and to setthe bridge plug 16, attached to the bridge plug setting and testingsection 208, then pressurizes a chamber therebetween for pressuretesting, as will be further described below.

Turning now to FIGS. 7 and 8, the top connection section 206 iscontained within a top connection housing 220 which extends between thefirst end 202 and a second end 222. The top connection housing 220 hasouter and inner surfaces 224 and 226, respectively, and includes aninner annular wall 228 which extends from the inner surface 226proximate to the first end 202 in a direction towards the second end soas to retain the first end connector 232 as will be described belowtherein. A plurality of optional vent ports 230 may extend through thetop connection housing 220 between the inner and outer surfaces 224 and226, providing hydrostatic fluidic communication with the surroundingfluid in the production casing 10.

A first end connector 232 extends between first and second ends 234 and236, respectively, and is connected to the wireline 18 by internalthreading 238 at the first end 234, as is commonly known. When an upwardforce is applied to the first end connector 232 in the directiongenerally indicated at 702, the apparatus 200 is activated, as will bemore fully explained below. The first end connector 232 includes anexpanded portion 240 adapted to slideably engage with the inner surface226 of the top connection housing 220.

An electronics housing 242 extends between first and second ends, 244and 246, respectively, and is secured to the second end 236 of the firstend connector 232 with a coupler 248, as is commonly known. Theelectronics housing 242 may be formed of a plurality of parts, as iscommonly known, and contains an electronic control system 250 therein,controlled by signals received through the wireline 18. The electronicscontrol system 250 is connected with wires through an electronics coiltube 252 to two solenoid valves, as will be set out below, and to aplurality of logging tools, such as, by way of non-limiting example,pressure sensors, temperature sensors and a marker fluid sensor. As bestseen in FIG. 8, the electronics coil tube 252 extends between first andsecond ends, 254 and 256, respectively, and extends into the electronicshousing 242 at the first end 254. The wires exit the electronics coiltube 252 at the second end 256 where they pass through a fluidicallysealed electronics passage 258 in a top cap 260. The annular top cap 260is secured to an annular upper housing 262 within the top connectionhousing 220 proximate to the second end 222 with threaded fasteners, asare commonly known, through a plurality of threaded fastener passages264. The upper housing 262 extends between first and second ends, 266and 268, respectively, and is secured within the second end 222 of thetop connection housing 220 with external threading or the like, as iscommonly known.

Referring now to FIGS. 7 and 9, the upper housing 262 includes first andsecond valve electronics passages 270 and 272, respectively, extendingaxially therethrough. The first and second valve electronics passages270 and 272 intersect an electronics C-channel 274. As seen on FIG. 8,the electronics passage 258 through the top cap 260 is aligned with theelectronics C-channel 274 such that the wires passing through theelectronics passage 258 may be directed to pass through the electronicsC-channel 274 and into the first and second valve electronics passages270 and 272. The first and second valve electronics passages 270 and 272are connected to first and second valves, as will be set out in moredetail below.

Turning back to FIGS. 7 and 8, a pump top rod 280 extends between firstand second ends, 282 and 284, respectively, and is secured to theelectronics housing 242 at the first end 282 and passes through acentral pump rod passage 276 in the top cap 260 and upper housing 262. Apump mandrel 290 extends between first and second ends 292 and 294,respectively, as best illustrated in FIG. 6, and is secured to thesecond end 284 of the pump top rod 280 at the first end 292 by means asare commonly known. As illustrated, the pump mandrel 290 includes asmaller radius first stage portion 291 extending from the first end 292and a larger radius second stage portion 293 extending from the secondend 294. As best shown in FIG. 8, the central pump rod passage 276includes a narrowed portion 278. The pump mandrel 290 is adapted tosealably pass through the narrowed portion 278 with a pump seal 800therebetween. The pump seal 800 separates the hydrostatic fluid in thetop connection section 206 from the pressurized fluid in the fluidcontrol section 210, as will be described in more detail below.

Turning now to FIGS. 8 and 10, the second end 268 of the upper housing262 includes a recessed channel 286 therein. As outlined above, thefirst and second valve electronics passages 270 and 272 pass through theupper housing 262, and are not connected with the recessed channel 286.The pump mandrel 290 passes through the recessed channel 286. Thepurpose of the recessed channel 286 will be set out in more detailbelow.

Turning back to FIG. 6, the fluid control section 210 includes atwo-stage piston pump 296 and valves 298. The pump 296 creates hydraulicpressure to pressurize and move fluid through the apparatus 200 whilethe valves 298 control the fluid flow direction and therefore thefunction of the apparatus 200, as will be set out in more detail below.

Referring to FIGS. 11 and 12, the pump 296 is contained within a pumphousing 300 with the pump mandrel 290 passing therethrough along thecentral axis 700. A releasable collar 330 is selectably attached to thepump mandrel 290 to switch between low and high-pressure pumpingoperation, as will be set out in more detail below.

The pump housing 300 extends between first and second ends 302 and 304,respectively, and is sealably secured to the upper housing 262 at thefirst end 302 with a threaded housing coupler 306, as is commonly known,with seals 802 and 804 therebetween. As illustrated in FIG. 12, thefirst and second valve electronics passages 270 and 272 pass through thepump housing 300, extending from the upper housing 262, as set outabove, and extend into a motor housing routing sleeve 420, which will befurther outlined below.

As best illustrated in FIG. 11, the pump mandrel 290 passes through acentral pump cavity 308, which extends between the first end 302 of thepump housing 300 and a second end 309 and has an inner surface 326. Thecentral pump cavity 308 is fluidically connected by the recessed channel286 at the first end 302 to a fluid intake passage 310 and a valvesupply passage 312. The fluid intake passage 310 includes an intakefilter or mesh 314 as are commonly known to remove contaminants as fluidis drawn therethrough from the surrounding fluid in the productioncasing 10. An intake check valve 316 within the fluid intake passage 310allows fluid flow in one direction only, as generally indicated by 704in FIG. 11. The valve supply passage 312 contains a valve supply checkvalve which allows fluid flow in one direction only, as generallyindicated at 706.

Referring now to FIGS. 13 and 14 fora detailed view and to FIG. 6 for afull-length reference view, the pump mandrel 290 is comprised of a firststage rod portion 320 extending from the first end 292 and a secondstage rod portion 322 extending from the second end 294 with a wideportion 324 therebetween. The first stage rod portion has a smallerdiameter than the second stage rod portion 322, the purpose of whichwill be set out below. In a first stage, low pressure pumpingconfiguration, the releasable collar 330 is secured to the second stagerod portion 322 of the pump mandrel 290 proximate to the wide portion324, as will be set out in more detail below.

The diameter of the wide portion 324 is selected to form an annularpassage 328 between the wide portion 324 and the inner surface 326,allowing fluid to pass thereby. The releasable collar 330 extendsbetween first and second ends 332 and 334, respectively, and has outerand inner surfaces 340 and 342, respectively, and is comprised of asealing portion 336 extending from the first end 332 and a releasablefinger portion 338 extending from the second end 334. The first end 332of the releasable collar 330 engages upon the wide portion 324 of thepump mandrel 290. The outer surface 340 of the sealing portion 336 isadapted to engage with the inner surface 326 with an outer seal 806therebetween. The inner surface 342 of the sealing portion 336 isadapted to engage upon the second stage rod portion 322 with inner seals808 therebetween. The releasable finger portion 338 is comprised of aplurality of collet fingers 344. Each collet finger 344 includes a firststage inner locking ridge 346 extending from the inner surface 342proximate to the second end 334 adapted to engage within an annularfirst stage locking groove 348 on the second stage rod portion 322. Whenthe first stage inner locking ridges 346 are engaged within the firststage locking groove 348, as illustrated in FIGS. 13 and 14, thereleasable collar 330 is secured to the pump mandrel 290. At the secondend 334, each collet finger 344 includes a second stage outer lockingblock 350, adapted to pass through the central pump cavity 308 when in afirst stage configuration, as illustrated in FIGS. 13 and 14. In asecond stage high pressure pumping configuration, the second stage outerlocking blocks 350 retain the releasable collar 330 at the second end309, as will be set out in more detail below.

The central pump cavity 308 includes a second stage annular lockinggroove 352 in the inner surface 326 at the second end 309 adapted toengage the second stage locking blocks 350 therein for the second stagehigh pressure pumping configuration, as will be set out below. As seenin FIG. 13, a hydrostatic pump passage 354 with an intake filter 356therein is fluidically connected to the second stage annular lockinggroove 352. As the pump mandrel 290 reciprocates within the central pumppassage 308, as will be set out below, the hydrostatic pump passage 354allows fluid from within the surrounding production casing 10 to enterand exit the pump passage 308 below the releasable collar 330.

The pump housing 300 includes an inner annular lip 358 at the second end309 of the central pump cavity 308 separating the central pump cavity308 from a second stage spring cavity 360. A pump unlock sleeve 362extends between first and second ends 364 and 366, respectively, and hasouter and inner surfaces, 368 and 370, respectively, and is adapted suchthat the inner surface 370 slideably engages upon the second stage rodportion 322 of the pump mandrel 290. The pump unlock sleeve 362 iscomprised of a wedge portion 372 extending from the first end 364 to anannular wall 382 and a spring engagement portion 374 extending betweenthe annular wall 382 and the second end 366. The wedge portion 372includes a tapered tip 376 at the first end 364 and is adapted to passbetween the inner annular lip 358 and the pump mandrel 290. As will beset out in more detail below, the wedge portion 372 with the tapered tip376 is adapted to bias the collet fingers 344 such that the second stageouter locking block 350 engages within the second stage annular lockinggroove 352 and to release the first stage inner locking ridge 346 fromthe first stage locking groove 348.

The second stage spring cavity 360 includes a widened portion 378defined by an annular wall 380. The spring engagement portion 374 of thepump unlock sleeve 362 is adapted such that the outer surface 368slideably engages upon the widened portion 378 of the second stagespring cavity 360. A second stage spring 384 extends between the innerannular lip 358 and the annular wall 382 of the spring engagementportion 374 within the second stage spring cavity 360, the purpose ofwhich will be set out further below.

As best seen on FIG. 14, a pump unlock pin sleeve 390 extends betweenfirst and second ends 392 and 394, respectively, and has outer and innersurfaces 396 and 398, respectively. The pump unlock pin sleeve 390 issecured within the pump housing 300 at the second end 304 by threadingor the like and extends into the motor housing routing sleeve 420. Thepump unlock pin sleeve 390 is adapted such that the inner surface 398 isslideably engaged with the pump mandrel 290 with an inner seal 810therebetween. The pump unlock pin sleeve 390 is comprised of a pinhousing portion 400 extending from the first end 392 to an annular wall402 and a narrow portion 404 extending from the annular wall 402 to thesecond end 394. The outer surface 396 of the pin housing portion 400 issealably engaged with the pump housing 300 at the first end 392 with anouter seal 812 therebetween. The outer surface 396 of the narrow portion404 is sealably engaged with the motor housing routing sleeve 420 at thesecond end 394 with an outer seal 814 therebetween.

The motor housing routing sleeve 420 includes an annular wall 406 spacedapart from the annular wall 402, forming an annular pin control cavity408 therebetween. Turning now to FIG. 13, a pin control passage 410fluidically connects the valve supply passage 312 with the annular pincontrol cavity 408, the purpose of which will be set out below.

Turning back to FIG. 14, the pump unlock pin sleeve 390 includes atleast one axial pin passage 412 therethrough, which extends between thefirst end 392 and the annular wall 402. A high-pressure pump pin 414extends between first and second ends 416 and 418, respectively, andoptionally has tapered ends as illustrated. A high-pressure pump pin 414extends through each axial pin passage 412 with a pin seal 816therebetween. The first end 416 of each high-pressure pump pin 414 isengaged upon the second end 366 of the pump unlock sleeve 362 and thesecond end 418 extends into the annular pin control cavity 408 andengages upon the annular wall 406 while in the first stage low-pressurepumping configuration. The purpose of the high-pressure pump pins willbe set out in more detail below.

Turning now to FIGS. 15, 16 and 17, the valves 298 are retained within avalve outer housing 430 which extends between first and second ends 432and 434, respectively. The valve outer housing 430 is secured to thepump housing 300 at the first end 432 with threading or the like with aseal 816 therebetween and to a main mandrel 500 at the second end 434with threading or the like with a seal 818 therebetween.

Referring now to FIG. 15, the motor housing routing sleeve 420 extendsbetween first and second ends 422 and 424, respectively, and engagesupon the second end 304 of the pump housing 300 with the first andsecond valve electronics passages 270 and 272 extending therethroughinto first and second valve connector cavities 426 and 428,respectively. The first and second valve connector cavities 426 and 428contain therein first and second electric connectors 436 and 438,respectively. The electronics from the electronic control system 250pass through the first and second valve electronics passages 270 and 272into the first and second valve connector cavities 426 and 428 andconnect to the first and second electric connectors 436 and 438,respectively, as is commonly known.

First and second electric motors 440 and 442, respectively, arecontained within a motor housing 444, which extends between first andsecond ends 446 and 448, respectively. The first and second electricconnectors 436 and 438 are connected to the first and second electricmotors 440 and 442, respectively, as is commonly known, proximate to thesecond end 424. A valve housing 450 extends between first and secondends 452 and 454, respectively, and contains first and second valvemanifold rods 456 and 458, respectively therein within first and secondvalve cavities 480 and 482, respectively. The valve housing 450 isaligned such that the first end 452 engages upon the second end 448 ofthe motor housing 444. The first and second electric motors 440 and 442control the positions of the first and second valve manifold rods 456and 458 with valve trains, as is commonly known.

The valve housing 450 includes first, second, third and fourth annularvalve passages, 460, 462, 464 and 466, respectively, therearoundproximate to the second end 454. A valve sleeve 470 extends betweenfirst and second ends 472 and 474, respectively and is adapted tosealably enclose and sealably separate the annular valve passages 460,462, 464 and 466 with a plurality of valve seals 820 therebetween. Thefirst, second and fourth annular valve passages, 460, 462 and 466,respectively, are fluidically connected to the second valve cavity 482while the third and fourth annular valve passages, 464 and 466,respectively, are fluidically connected to the first valve cavity 480.The valve manifold rods 456 and 458 are controlled by the first andsecond electric motors 440 and 442 to adjust the fluidic connectionsbetween the annular valve passages, as will be set out in more detailbelow.

Turning now to FIG. 16, the valve supply passage 312 extends from thepump housing 300 and is fluidically connected to the third annular valvepassage 464 and into the first valve cavity 480. A first pressurizingpassage 484 is fluidically connected to the second valve cavity 482through a valve connection passage 486, as seen on FIGS. 15 and 16, andextends into the bridge plug setting and testing section 208, as will bedescribed more fully below. A second pressurizing passage 488 isfluidically connected to the first annular valve passage 460 and intothe second valve cavity 182. The second pressurizing passage 488 isfluidically connected to the first valve cavity 480 through a valveconnection passage 490, as seen on FIG. 15.

Turning now to FIG. 17, a hydrostatic passage 492 is fluidicallyconnected to the second annular valve passage 462, which is connected tothe second valve cavity 482. The hydrostatic passage is fluidicallyconnected to the surrounding hydrostatic fluid in the production casing20 through a filter 494. The hydrostatic valve passage 492 is alsofluidically connected to the first valve cavity 480 through a valveconnection passage 496, as seen on FIG. 15. An electronics passage 476extends from a connecting passage 478 in the motor housing 444 andextends into the main mandrel 500. The connecting passage 478fluidically connects to the first valve connector cavity 426 allowingfor electrical connections to pass therethrough and extend into theelectronics passage 476, the purpose of which will be set out below.

Turning now to FIGS. 18 through 21, the first and second valve cavities480 and 482 are illustrated schematically with the first and secondvalve manifold rods 456 and 458, respectively, therein and the passagesdescribed connected thereto. In FIG. 18 the valves 298 are illustratedin a first or placement position. In this position, pressurized fluidfrom the valve supply passage 312 enters the first valve cavity 480 butis blocked from entering the second valve cavity 482. The first andsecond pressurizing passages 484 and 488 are fluidically connected withthe hydrostatic passage 492 through the second valve cavity 482.

FIG. 19 illustrates a second or element set position. In this position,pressurized fluid from the valve supply passage 312 enters the firstvalve cavity 480 and is fluidically connected to the second valve cavity482 through the fourth annular valve passage 466. The pressurized fluidis fluidically connected to the first pressurizing passage 484 throughthe second valve cavity 482. The second pressurizing passage 488 isfluidically connected to the hydrostatic passage 492 through the firstvalve cavity 480.

A third or pressurizing position is illustrated in FIG. 20. In thisposition, pressurized fluid from the valve supply passage 312 enters thefirst valve cavity 480 and is fluidically connected to secondpressurizing passage 488. The first pressurizing passage 484 is isolatedand maintains its pressure. The hydrostatic passage 492 is also isolatedin this position.

FIG. 21 illustrates the fourth or release position for the valves 298.In this position, pressurized fluid from the valve supply passage 312enters the first valve cavity 480 and is fluidically connected to thesecond valve cavity 482 through the valve connection passage 490 and thefirst annular valve passage 460. The first and second pressurizingpassages 484 and 488 are also fluidically connected to the second valvecavity 482. The second valve cavity 482 is fluidically connected to thehydrostatic passage 492, therefore in this position, all pressurizedfluid is released from the apparatus 200 through the hydrostatic passage492.

Referring back to FIG. 6, the retention section 212 includes a slipcollet 214 on a main mandrel 500. The main mandrel 500 extends betweenfirst and second ends 502 and 504, respectively, and includes a centralaxial cavity 506 adapted to slideably retain the second end 294 of thepump mandrel 290 therein. As illustrated in FIG. 15, the first end 502of the main mandrel 500 engages upon the second end 454 of the valvehousing 450 and is retained within the valve outer housing 430 at thesecond end 434 with a seal 818 therebetween. As illustrated in FIG. 16,the first and second pressurizing passages 484 and 488 extend into themain mandrel 500, as will be set out further below. As illustrated inFIG. 17, the hydrostatic passage 492 extends into the main mandrel 500and is fluidically connected to the surrounding fluid in the productioncasing 200 through the filter 494. The electronics passage 476 alsoextends into the main mandrel 500.

As illustrated in FIG. 22, the slip collets 214 includes a plurality ofaxial drag collet arms 216 secured within and retained by a collet cage218. As illustrated in FIG. 32 the collet cage 218 includes a pluralityof longitudinally extending openings 219 sized to receive the colletarms 216 therethrough. The collet arms extend to a distal grippingportion 217 and may include a one or more grip enhancement such as ahardened steel stud or plug extending therefrom as is commonly known.The collet cage 218 is may be formed of on or more components andincludes a plurality of collet pins 510 extending therefrom intoengagement with a J-slot 520 in the main mandrel 500 as set out below. Aspring 215 may be located under an end distal to the gripping portion217 so as to bias such top end against the wellbore 18 thereby providinga starting drag force for the collet arms and J-slots.

The main mandrel 500 extends through the collet cage 2018 and pluralityof collet arms 214 as illustrated in FIG. 22 as well as a colletextension cone 540. As will be described in more detail below, thecollet cage 218 with the collet arms 214 attached thereto, shiftsaxially over the main mandrel 500 such that the collet arms 214 engageupon the cone 540, extending the collet arms 214 such that the apparatus200 may be fixed in place within the wellbore 10 as will be more fullydescribed below.

Turning now to FIG. 23, a perspective view of the main mandrel 500 isillustrated. The main mandrel 500 includes a plurality of axial J-slots520 thereon, distributed evenly therearound. The J-slots are formed ofupper and lower portions to permit the collet cage and arms to beselectably axially displaced along the main mandrel and into engagementwith the cone 540. In particular, the J-slots 520 include a plurality oflower J-slots 522 extend between lower slot first ends 524 and a slotcross-over 526. In the present embodiment of the invention, six lowerJ-slots 522 are evenly distributed around the main mandrel 500 althoughit will be appreciated that more or less may also be utilized. The upperJ-slots are axially offset from the lower J-slots 522 and alternatebetween short upper J-slots 528 and long lower J-slots 530. In thepresent embodiment of the invention, three short upper J-slots 528alternate with three long upper J-slots 530. The short upper J-slots 528extend between the slot cross-over 526 and the short upper J-slot secondend 532. The long upper J-slots 530 extend between the slot cross-over526 and the long upper J-slot second end 534. The lower J-slots 524 areaxially offset from the upper J-slots 528 and 530 such that each upperJ-slot, 528 or 530, is positioned axially between a pair of lowerJ-slots 522. As illustrated, the lower J-slots 522 have angled upperslot ends 536 and the upper J-slots 528 and 530 have angled lower slotends 538 at the slot cross-over 526. Angled upper and lower slot ends,536 and 538, respectively, are angled in opposite directions, thepurpose of which will be set out below.

With reference back to FIG. 22, the collet cage 218 may include aplurality of collet pins 510 extending therefrom to be received withinthe J-slot 520. In particular, a plurality of collet pins 510 may beevenly spaced around the main mandrel 500 so as to correspond to thenumber of long or short upper J-slots 528 or 530 so as to ensure thatall collet pins 510 are be located within either long or short upperJ-slot. The collet pins 510 may be positioned within the collet cage 218by a collet pin bushing 512 retained within an annular groove in thecollet cage 218 with clearance fits so as to permit rotation of thecollet pin busing about the collet cage 218 and main mandrel 500.

With reference to FIGS. 22 and 24, the cone 540 is slidably locatablealong the main mandrel 500 and includes a frustoconical colletengagement surface 542 at a top end thereof and an outer cylindricalextension 544 extending towards a bottom end thereof. The cylindricalextension 544 is spaced apart from the main mandrel 500 so as to form anannular cavity 546 therebetween. A seal as is commonly known 550 ispositioned downstream of the cone 540 and includes top and bottom sealbacking rings 552 and 554, respective to opposite sides thereof. The topbacking ring 552 includes a cylindrical extension extending 556therefrom sized to be received within the annular cavity 546 wherein theouter cylindrical extension 544 and inner cylindrical extension aresecured to each other with shear pins 558 operable to be sheared by asufficiently large upward force applied through the wireline to releasethe collet arms 214 and seal 550 so as to facilitate removal of theapparatus in the event of a problem or emergency. The bottom backingring 554 is engaged by a seal actuating piston 560 located around themain mandrel 500 within a seal engagement chamber 564. The sealengagement chamber 564 is in fluidic communication with the firstpressurizing passage 484 so as to bias the seal actuating piston 450towards the top seal backing ring 552 thereby compressing the seal 550between the top and bottom seal backing rings 552 and 554 uponpressurization of this passage as will be more fully set out below.

As illustrated in FIG. 24, the bridge plug setting and testing section208 also includes a testing fluid injector 600 adapted to discharge amarker fluid into the annulus between the apparatus 200 and the wellboreso as to enable the apparatus to test the integrity of the seal 550 aswell as the bridge plug and wellbore wall as will be more fullydescribed below. The injector 600 comprises an injector bore 602extending between first and second ends, 604 and 606, respectively andhaving an injector piston 610 therein. The injector bore 602 is influidic communication with the second pressurizing passage 488 throughbore 606 in the main mandrel 500. The second end 606 of the injectorbore is in fluidic communication with the exterior of the apparatus 200through an injector check valve 612 adapted to permit a quantity of themarker fluid to be passed therethrough when a sufficient pressure isachieved in the second pressurizing passage 488 and therefore alsowithin the injector bore 602. By way of non-limiting example, thepressure required to inject the marker fluid may be selected to besimilar to or above the test pressure such as, by way of non-limitingexample, 1000 psi above the pressure required to pressurize the annulusbetween the apparatus 200 and the well bore 18 as set out below.

The injector 600 also includes an annular reservoir 620 formed aroundthe main mandrel extending between first and second ends, 622 and 624,respectively. The annular reservoir 620 includes an annular reservoirpiston 626 therein and may be initially located proximate to the firstend 622 thereof wherein the remainder of the annular reservoir 620 isfilled with a quantity of the marker fluid. The first end 622 is influidic communication with the first pressurizing passage 484 throughconnection passage 628 and charging check valve 630. The charging checkvalve 630 is adapted to permit fluid from the first pressurizing passage484 to enter the first end 622 of the annular reservoir 620 upon asufficient pressure being achieved. The second end 624 of the annularreservoir 620 is in fluidic communication with the second end 606 of theinjector bore 602. The injector 600 may also include fill ports, as arecommonly known for refilling the annular reservoir 620 with areplacement quantity of the marker fluid. The marker fluid may beselected to be any know fluid which can be detected as different fromthe existing fluid within the wellbore, such as, by way of non-limitingexample, saline or oil.

Turning now to FIG. 25, the bridge plug actuator 660 is illustrated at asecond end 204 of the apparatus. The bridge plug actuator 660 comprisesan outer housing 662 securable to the main mandrel 550 and forming aninner cylinder 664 therein. As illustrated in FIG. 25, the outer housingmay include an extension 666 spanning to the main mandrel 550 whichincludes a first end wall 668 at a top end of the cylinder 664. A secondend wall 670 extends inwardly from the outer housing 662 to define thebridge plug actuation cylinder 664 therebetween. The bridge plugactuator 660 includes a piston 672 within the bridge plug actuationcylinder 664 with a shaft 674 having a blind bore 676 extendingtherethrough to both directions from the piston 672. In particular theshaft 674 has a sufficient length to extend through the first and endwalls 668 and 670 at all positions of the piston 672. The blind bore 676extend to a transfer cavity 667 within the extension 666. As illustratedin FIG. 25, the second pressurizing passage 448 extends to the end ofthe main mandrel 500 and therefore is in fluidic communication with thetransfer cavity 667 whereas the first pressurizing passage 484 isblocked. The blind bore 676 also includes actuation ports 678 extendingthrough the shaft 674 into the region between the second end wall 670and the piston 672 so as to displace the piston upward in a directiongenerally indicated at 671 when the second pressurizing passage 488 ispressurized.

A bridge plug connector 680 is provide at the distal end of the shaft674 which includes the blind bore 676 therein and a narrowed or neckedportion 682 at a position where the blind bore also passes therethrough.

In operation, a bridge plug (not shown) as are commonly known may besecured to the bridge plug connector 680. A user then locates theapparatus at a desired location in the well to be tested and abandoned.Thereafter, the operator pulls up on the wireline 18 to drag the collets214 against the well bore so as to radially shift the collet pins 510into the long bottom J-slots 530 thereby permitting the collet cage 218and the collet arms 214 to shift towards the cone 540. Further upwardmotion of the main mandrel 550 will pull the cone under the collet arms214 further engaging the distal ends 217 thereof into the wellbore wallthereby fixing the location of the collet arms within the wellbore. Itwill be appreciated that during such setting motion, the first andsecond valve manifold rods 456 and 458 may be positioned as illustratedin FIG. 18 so as to prevent any fluid leaving the central pump cavity308 through the valve supply passage 312 and therefore will also preventmovement of the pump mandrel 290 relative to the main mandrel 500.

Once the collet arms 214 are set, the first and second valve manifoldrods 456 and 458 may be positioned as illustrate in FIG. 19. In suchposition, movement of the pump mandrel 290 relative to the main mandrel500 will be permitted thereby pressurizing the first pressurizationpassage 484 by the movement of the pump mandrel 290. Such pressurizationwill enter the seal engagement chamber 564 so as to displace the sealpiston and compress the top and bottom retaining rings 552 and 554together thereby compressing and expanding the seal into contact withthe wellbore wall. The pressurization of the first pressurizationpassage 484 will also enter the first end 662 of the annular reservoir620 thereby displacing the annular piston 626 and pressurizing theinjection cylinder 602 as well as ensuring the injection piston 610 isretraced

Once the seals are set, the first and second valve manifold rods 456 and458 may be moved to the positions illustrated in FIG. 20 to pressurizethe second pressurization passage 488 and de-couple the firstpressurization passage 484 from the valve supply passage 312. As thesecond pressurizing passage 488 is pressurized, the piston 672 isdisplaced upwards in a direction generally indicated at 671 until thebridge plug is engaged upon the second end 204 of the apparatus toextend or engage the bridge plug as is commonly known. Thereafterfurther pressurizing of the second pressurizing passage 480 willincrease the pressure between the piston 672 and the second wall 670until the force applied to the shaft is sufficient to rupture or breakthe shaft at the necked portion 682 as illustrated in FIG. 26. At thattime, the pressure within the second pressurization passage 488 ispermitted to enter the annulus between the apparatus 200 and thewellbore between the seal 550 and the bridge plug. Pressure transducers,which may be located at any suitable location in the apparatus, such as,by way of non-limiting example, at the distal end of the main mandrel500 or within the threaded fastener passage 264 so as to measure thepressure within the central pump cavity 308 or valve supply passage 312may be provided to measure and log the pressure within the wellboreannulus to determine if there is a leak within this region of thewellbore or past the seal 550 or bridge plug. Further pressurizing ofthe annulus may thereafter be provided by additional pumping of the pumpmandrel 290 as set out below.

Additionally, while the first and second valve manifold rods 456 and 458are positioned as illustrated in FIG. 20, the second pressurizingpassage 488 will introduce the pressurized fluid to the first end 604 ofthe injector cylinder to bias the injector piston 610 towards the secondend 606 of the injector cylinder. Such movement of the injector piston610 will be resisted until the pressure within the injector cylinder 602is sufficient to overcome the spring in the injector check valve 612 atwhich time the marker fluid contained therein will be ejected into theannulus. Marker fluid sensors located upstream of the seal 550, such as,by way of non-limiting example, on the frustoconical surface of thecone, thereafter monitor for the presence of the marker fluid todetermine if there is a leak past the seal 550. It will be appreciatedthat the pressure within the annulus may be maintained for apredetermined length of time to determine if there is a leak therefrom.

With reference to FIGS. 11 and 27, the pump mandrel 290 may be operatedto pressurize the first or second pressurizing passages 484 or 488 asset out above by lifting up on the first end connector 232 with thewireline 18. Such movement of the first end connector 232 will also liftup the pump top rod 280 and pump mandrel 290 so as to displace the pumpmandrel 290 and releasable collar 330 within the central pump cavity 308thereby displacing the fluid contained therein through the valve supplypassage 312, the use of which is set out above. When the pump mandrelhas reached the end of its stroke as illustrated in FIG. 27, thewireline 18 may then be lowered permitting the pump mandrel to return tothe initial position as illustrated in FIG. 11. During this movement,the fluid intake passage 310 and intake check valve 316 permit fluidsurrounding the apparatus 200 to enter the central pump cavity 308 so asto provide the next amount of fluid to be discharged into the valvesupply passage 312 during the next stroke from the position illustratedin FIG. 11 to the position illustrated in FIG. 27. As many strokes asnecessary to pressurize the apparatus 20 may be utilized.

As illustrated in FIGS. 13, 14 and 30 upon reaching a predeterminedpressure, which may correspond to the maximum pull rating of thewireline 18, the pressure passing through the valve supply passage 316and therefore into the annular pin control cavity 408 will exert apressure upon the high pressure pump pins 414 so as to overcome thesecond stage spring 384 thereby moving the tapered tip 376 and wedgeportion 372 of the pump unlock sleeve 362 as illustrated in FIG. 30. Inthis position the pump unlock sleeve 362 will disengage the first stateinner locking ridges 346 from the first state locking groove 348 andengaging the second state outer locking blocks 350 within the secondstage annular locking groove. Such position will thereafter decouple thereleasable collar 330 from the pump mandrel 290 thereby permitting thepump mandrel 290 to move independently of the releasable collar. It willbe appreciated that in the first stage as illustrated in theconfiguration of FIGS. 13 and 14, the pump volume of the pump mandrel290 will comprise the volume of the central pump cavity 308 minus thevolume of the pump mandrel 290. It will be further appreciated that inthe second stage as illustrated in the configuration of FIG. 30, thepump volume will thereafter be the difference in volume between thefirst and second stage portions 291 and 293. It will be appreciated thatsuch reduction in the pumping volume at the second stage as illustratedin FIG. 30 will require less force on the wireline 18 thereby permittinga greater pressure to be developed in the system while remaining withinthe weight ratings for the wireline 18.

Turning now to FIG. 21, once a bridge plug has been set and the wellborepressure tested, the first and second valve manifold rods 456 and 458may be positioned as illustrated in FIG. 21 to release the pressurewithin each of the first and second pressurizing passages 484 and 488.It will be appreciated that such release will permit the releasablecollar 330 to re-engage upon the pump mandrel 290. Such release willalso vent the fluid within the seal engagement chamber 564 so as topermit the pressure upon the seal 550 to be released thereby disengagingitself from the wellbore wall. Subsequent downward movement of the firstend connector 232 will displace the collet pins 510 within the J-slots520 to the end of the lower slots 522 so as to permit the cone 540 to bewithdrawn from under the collet arms 214 thereby disengaging them fromthe wellbore. At such time, the apparatus may thereafter be removed fromthe wellbore or moved to a different position as desired. Optionally,the apparatus 200 may include a burst disk (now shown) at a locationalong the valve supply passage 312 or any other location in fluidiccommunication therewith such that an operator may over pressurize thevalve supply passage 312 with the pump mandrel 290 so as to rupture theburst disk thereby venting the pressure within the system to allowremoval of the apparatus.

Turning now to FIG. 33, the electronics control system 250 includes aprocessor circuit 900 operable to receive control signals 902 throughthe wireline 18 or through any other means as are commonly known. Theprocessor circuit 900 may also include an associated battery 904 or mayoptionally be provided with a power input supplied through the wireline18. As illustrated in FIG. 33, the processor circuit 900 receivessignals from the pressure sensors 908 and test fluid sensors 910 asdescribed above for measuring the pressure within the annulus betweenthe apparatus 200 and the wellbore 10 and for monitoring for thepresence of the marker fluid above the seal 550. The processor circuit900 is also adapted to control the position of the first and secondelectric motors as set out above. The electronics control system 250will include a memory 906 for storing the readings of the pressure andmarker fluid sensors however it will be appreciated that the electronicscontrol system 250 may also transmit these readings to an operatorthrough known methods.

More generally, in this specification, including the claims, the term“processing circuit” is intended to broadly encompass any type of deviceor combination of devices capable of performing the functions describedherein, including (without limitation) other types of microprocessingcircuits, microcontrollers, other integrated circuits, other types ofcircuits or combinations of circuits, logic gates or gate arrays, orprogrammable devices of any sort, for example, either alone or incombination with other such devices located at the same location orremotely from each other. Additional types of processing circuit(s) willbe apparent to those ordinarily skilled in the art upon review of thisspecification, and substitution of any such other types of processingcircuit(s) is considered not to depart from the scope of the presentinvention as defined by the claims appended hereto. In variousembodiments, the processing circuit 900 can be implemented as asingle-chip, multiple chips and/or other electrical components includingone or more integrated circuits and printed circuit boards.

Computer code comprising instructions for the processing circuit(s) tocarry out the various embodiments, aspects, features, etc. of thepresent disclosure may reside in the memory 906. In various embodiments,the processing circuit 900 can be implemented as a single-chip, multiplechips and/or other electrical components including one or moreintegrated circuits and printed circuit boards. The processing circuit900 together with a suitable operating system may operate to executeinstructions in the form of computer code and produce and use data. Byway of example and not by way of limitation, the operating system may beWindows-based, Mac-based, or Unix or Linux-based, among other suitableoperating systems. Operating systems are generally well known and willnot be described in further detail here.

Memory 906 may include various tangible, non-transitorycomputer-readable media including Read-Only Memory (ROM) and/orRandom-Access Memory (RAM). As is well known in the art, ROM acts totransfer data and instructions uni-directionally to the processingcircuit 900, and RAM is used typically to transfer data and instructionsin a bi-directional manner. In the various embodiments disclosed herein,RAM includes computer program instructions that when executed by theprocessing circuit 900 cause the processing circuit 900 to execute theprogram instructions described in greater detail below.

While specific embodiments of the invention have been described andillustrated, such embodiments should be considered illustrative of theinvention only and not as limiting the invention as construed inaccordance with the accompanying claims.

What is claimed is:
 1. A well abandonment tool comprising: an elongatehousing extending between top and bottom ends locatable within awellbore having a longitudinal pumping cylindrical bore therein; awellbore seal located around said housing operable to engage upon saidwellbore and to be expanded into contact therewith upon an upward motionof said housing so as to seal an annulus between said housing and saidwellbore; a bridge plug engagement connector adapted to secure a bridgeplug thereto at a position below said bottom end of said housing; and apumping piston longitudinally moveably located within said pumpingcylinder, said pumping piston being suspended from a wireline whereinlongitudinal movement of said pumping piston discharges a fluid into abridge plug activation chamber having a movable cylinder adapted to drawsaid bridge plug engagement connector against said bottom end of saidhousing so as to expand said bridge plug into engagement with saidwellbore.
 2. The well abandonment tool of claim 1 wherein said bridgeplug engagement connector includes a frangible portion and wherein saidbridge plug engagement connector includes a cavity therein through saidfrangible portion in fluidic communication with said bridge plugactivation chamber.
 3. The well abandonment tool of claim 2 furthercomprising at least one valve adapted to selectably direct said fluidfrom said pumping cylinder to said bridge plug activation chamber. 4.The well abandonment tool of claim 3 wherein said at least one valve isadapted to isolate said fluid within said pumping cylinder so as toprevent movement of said pumping piston therein.
 5. The well abandonmenttool of claim 3 further comprising a testing fluid injector assemblyadapted to discharge a quantity of a testing fluid therefrom into apressurized annulus between said housing and said wellbore and betweensaid wellbore seal and said bridge plug.
 6. The well abandonment tool ofclaim 5 wherein said testing fluid injector comprises an injectorcylinder having an injector piston therein and a reservoir cylinderhaving a reservoir piston therein.
 7. The well abandonment tool of claim6 wherein said reservoir piston is displaced by said fluid directed tosaid bridge plug activation chamber so as to pressurize said injectorcylinder.
 8. The well abandonment tool of claim 6 wherein said at leastone valve is adapted to selectably direct said fluid to said injectorpiston so as to displace said piston therein so as to discharge saidtesting fluid therefrom.
 9. The well abandonment tool of claim 8 whereinsaid injector cylinder includes a check valve having an opening pressureselected to prevent said discharge of said testing fluid before saidbridge plug is set.
 10. The well abandonment tool of claim 3 furthercomprising a processing circuit adapted to control said operation ofsaid at least one valve.
 11. The well abandonment tool of claim 10wherein said processing circuit is adapted to monitor said pressurewithin said pressurized annulus and presence of said testing fluid atsaid test sensors thereabove.
 12. The well abandonment tool of claim 1wherein said pumping piston includes a first stage ring selectablysecured therearound so as to provide an increased pumping volume whensecured thereto.
 13. The well abandonment tool of claim 12 wherein saidfirst stage ring includes a plurality of piston collet arms each havinga radially inwardly extending protrusion engaged within an annularpiston groove on said pumping piston so as to secure said second stagering to said pumping piston.
 14. The well abandonment tool of claim 13wherein said each of said pumping piston collet arms includes a radiallyoutwardly extending protrusion adapted to be engaged within an annularcylinder groove in said pumping cylinder.
 15. The well abandonment toolof claim 14 further comprising a first stage disengagement wedge ringadapted to be slidably located under said plurality of piston colletarms so as to disengage said inwardly extending protrusions from saidannular piston groove and engage said outwardly extending protrusionsinto said annular cylinder groove.
 16. The well abandonment tool ofclaim 15 further comprising at least one spring biased second stagepiston fluidically connected with said output form said pumping cylinderso as to displace said first stage disengagement wedge ring upon saidpumping cylinder reading a predetermined pressure.
 17. The wellabandonment tool of claim 1 further comprising a plurality of slip armsexpandable into engagement with said wellbore wall by a cone locatedaround said housing between said slip arms and said wellbore seal. 18.The well abandonment tool of claim 17 wherein said slip arms areretained around said housing on a slip arm ring.
 19. The wellabandonment tool of claim 18 wherein said slip arm ring includes atleast one radially inwardly extending j-pin, wherein said slip arm ringis selectably longitudinally positionable along said housing by rotatingsaid j-pin into alternating short and long longitudinal slots on anouter surface of said housing.
 20. The well abandonment tool of claim 17wherein said wellbore seal is longitudinally compressed between saidcone and a wellbore seal backing protrusion extending from said housing.21. The well abandonment tool of claim 20 further comprising a wellboreseal retention piston engaged upon a bottom end of said wellbore sealwherein said wellbore retention piston is biased towards said wellboreseal by said pressure of said fluid directed towards said bridge plugengagement chamber.
 22. A method for abandoning a wellbore comprising:locating a housing within a wellbore above a location to be sealed;pulling upwardly on a wireline secured to a pumping piston within saidhousing so as to draw a bottom end of said housing upwards therebyextending a seal element located along said housing into engagement withsaid wellbore; pulling upwardly on said wireline so as to displace saidpumping piston within a cylindrical bore within said housing so as todischarge a fluid therefrom; directing said discharged fluid into abridge plug activation chamber adapted to draw a bridge plug engagementconnector against a bottom end of said housing so as to expand a bridgeplug secured thereon into engagement with said wellbore.
 23. The methodof claim 22 further comprising further pressurizing said bridge plugactivation chamber after said bridge plug is secured so as to shear afrangible portion of said bride plug engagement connector releasing saidfluid into a pressurized annulus between said housing and said wellborebetween said seal and said bridge plug.
 24. The method of claim 22further comprising injecting a quantity of a testing fluid into saidpressurized annulus and monitoring above said seal for a presence ofsaid testing fluid.
 25. The method of claim 24 further comprisingmonitoring a pressure within said pressurized annulus.